The Backbone • Phosphorous • Carbohydrate (sugar) Ring
Deoxyribonucleic Acid • DNA • The carbohydrate ring on the DNA is DEOXY • There is a hydrogen instead of a hydroxyl group on the carbohydrate ring. If there is a hyrdoxyl group it is called a ribonucleic acid. RNA DNA RNA
The Backbone • The phosphorus group and carbohydrate ring link together to make the backbone of DNA • What other part are we missing to DNA?
Nucleotides • There are 4 nucleotides in DNA. • Does anyone remember what they are? • Adenine [A] • Thymine [T] • Guanine [G] • Cytosine [C]
Purines and Pyrimidines • Purine • Adenine and Guanine • Pure As Gold • Purines have a 2 ring structure • Gold has twice the value of rocks • Pyrimidine • Thymine and Cytosine • Pyrimidines have a one ring structure
Chargaff’s Rule • Do you remember Watson and Crick? • They used Chargaff’s Rule and the double helix structure of DNA to figure out that: • AND THIS IS IMPORTANT • Adenine PAIRS with Thymine • Cytosine PAIRS with Guanine
Was that a Lot? Let’s Review • Please make sure all of this is in your notes!!!! • What 2 things make up the backbone of DNA? • What does Deoxy mean? • What are the 4 nucleotides? • What is the difference between a Purine and a Pyrimidine? • Which nucleotides are Purines? Which are Pyrimidines? • Which nucleotide pairs with witch other one?
Now Let’s Make our Own DNA • Cut out some nucleotides. • Use one color for each type • It’ll help a lot if you cut out equal numbers of C’s and T’s and equal numbers of A’s and G’s. You’ll want about 20 nucleotides in total! • Label these nucleotides with their proper letters. • Label them as purines and Pyrimidines • Pu or py Cut out a DNA backbone from the other color. (Just make it a long rectangle for simplicity) Glue ONE STRAND (1 backbone+about 10 nuceltides in any sequence) on the sheet of white paper Then give your sheet to a partner and have them write their name on it and COMPLETE the second strand of DNA. Glue it and hand it in.